The present disclosure relates to a load transfer apparatus for transferring loads in an aircraft structure (for example a wing), and particularly to a load transfer apparatus for transferring shear loads (for example transverse shear loads in a wing). The disclosure also relates to a method of designing a load transfer apparatus.
It is known to transfer loads between two components, using a multiplicity of interlocks. Each interlock typically comprises a male member received in a female member. The male/female members tend to be sufficiently stiff that if there is play between the male and/or female member in an interlock (which may arise due to wear, tolerances, deflections etc.) then that interlock no longer acts to transfer loads, and the loads are borne by the remaining interlocks. For safety critical applications, it is necessary to provide multiple redundant interlocks (in effect, one assumes that only a percentage of the total number of interlocks will be acting to transfer load at any one time). However, having redundant interlocks in this manner can add extra weight/bulk to the load transfer apparatus.
It is often necessary to safely and reliably transfer loads within an aircraft structure. For example, some aircraft are provided with wing tip devices which may be folded to reduce the span of the aircraft on the ground (compared to when the aircraft is configured for flight). The wing tip devices may, for example, be configurable between: (i) a flight configuration for use during flight and (ii) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that the span of the aircraft is reduced. It may be desirable to transfer loads between the wing and wing tip device in such an aircraft. For example it may be desirable to transfer torsional loads, between the wing and the wing tip device.
The present invention seeks to provide an improved load transfer apparatus, especially (but not necessarily exclusively) for transferring loads in an aircraft wing.